1. Field of the Invention
The present invention relates to a liquid crystal display device which can control the viewing angle of a display image to a wide viewing angle and a narrow viewing angle, and an electronic device using the same.
2. Description of the Related Art
Conventionally known as a viewing-angle limiting type display device which can limit a viewing angle is a liquid crystal display device which has an image display panel comprising a liquid crystal display panel, and a viewing-angle limiting element disposed over one side of the image display panel.
As disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 2004-133334, the viewing-angle limiting element is provided with aligning films and electrodes. The aligning films are provided on the inner surfaces of a pair of substrates opposite to each other with a gap therebetween, and each has different directions of an aligning treatment for different segment regions provided by dividing an area of the image display panel corresponding to the screen thereof. The electrodes are provided on both of the opposing inner surfaces of the pair of substrates, and formed in such a predetermined pattern as to correspond to the individual segment regions. The liquid crystal molecules of a liquid crystal layer of the viewing-angle limiting element sealed between the pair of substrates are aligned in an aligning state which has a viewing angle in a direction inclined in one direction with respect to the normal line direction of the image display panel, and an aligning state which has a viewing angle in a direction inclined opposite to the former direction, for each segment region.
This viewing-angle limiting type liquid crystal display device applies a voltage between the electrodes of the viewing-angle limiting element and reduces a visibility from an oblique direction, thereby limiting the viewing angle of a display image on the image display panel. When no voltage is applied between the electrodes of the viewing-angle limiting element, i.e., when the viewing-angle limiting element is not in operation, the display image on the image display panel is viewed at a wide viewing angle. In contrast, when the voltage is applied between the electrodes of the viewing-angle limiting element, the display image of the viewing-angle limiting element appears as a display of each segment region having a viewing angle in a direction inclined in one direction of the viewing-angle limiting element and another display of other individual segment regions having a viewing angle in a direction inclined in the opposite direction. Accordingly, when viewed from a direction inclined in one direction with respect to the normal line direction of the image display panel and a direction inclined in the opposite direction, the display image on the image display panel is displayed partially hidden in accordance with each segment region of the viewing-angle limiting element, and cannot therefore be recognized entirely, so that the viewing angle of the display image is limited.
However, the conventional viewing-angle limiting type liquid crystal display device requires a complex aligning treatment (rubbing treatment for aligning films) on the inner surfaces of the pair of substrates of the viewing-angle limiting element which has different directions for different segment regions for aligning the liquid crystal molecules of the liquid crystal layer of the viewing-angle limiting element in different aligning states in such a way that the liquid crystal molecules have different viewing-angles for individual segment regions. This raises a problem that its manufacture is difficult.